:root {
  --primary-color: #4a4a4a;
  --secondary-color: #6c757d;
  --background-color: #f8f9fa;
  --card-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
}

body {
  font-family: 'Noto Sans SC', sans-serif;
  background-color: var(--background-color);
  color: var(--primary-color);
}

.navbar {
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.card {
  background: white;
  border-radius: 0.8rem;
  box-shadow: var(--card-shadow);
  transition: transform 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
}

.timeline {
  border-left: 2px solid var(--secondary-color);
  position: relative;
  padding-left: 2rem;
}

.timeline-item {
  margin-bottom: 2rem;
  position: relative;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2.35rem;
  top: 0.5rem;
  width: 1rem;
  height: 1rem;
  background: var(--secondary-color);
  border-radius: 50%;
}

footer {
  background-color: rgba(0, 0, 0, 0.05);
  padding: 2rem 0;
  margin-top: 4rem;
}

.social-links a {
  color: var(--secondary-color);
  margin: 0 1rem;
  transition: color 0.3s ease;
}

.social-links a:hover {
  color: var(--primary-color);
}